The gecko walks on sticky pads

March 8, 2012 by Roelof Kleis, Wageningen University

As sticky as a gecko. Wageningen UR Veni-researcher Marleen Kamperman tries to stick with plastic material full of microscopic rods.

Dancing on the ceiling. Lionel Ritchie's smash hit in the eighties. The song's video clip shows him walking upside down on the ceiling. Just an illusion, of course. , however, can do that, like countless other . Among the bigger animals, the gecko stands out as an example. It can run upside down effortlessly.

can do that because of complex structures on their feet, explains Kamperman. These are bundles of tiny hairs each ending in a sort of little flap. Hundreds of thousands of these little flaps stick to every surface by adhesion and without any other material aid. The work is done by so-called forces. Theoretically speaking, anyway. Kamperman says that it is not exactly clear what the mechanism is.

Not that it matters. Kamperman isn't planning to make gecko feet in exact detail. 'That won't be wise. A gecko foot is a very complex organic system. One should focus on the major issues, get to the essence of the design and copy that. This is what I'm doing now.' And this essence lies in the tiny hairs with the flaps.

Kamperman tries to capture this essence in plastic. She describes her first attempts in the latest issue of Acta Biomaterialia. Kamperman's gecko feet is a little plastic sheet (polydimetylsiloxane) covered with countless tiny rods which resemble studs measuring about ten micrometres in diameter. A gecko would not recognize this, but it works.

To a certain extent, that is. Kampermans' gecko skin sticks well to a base of pure silicon. But hardly any surface is as glassy smooth as that. The wheels fall off when the surface is a little rougher. 'So more is needed than just making tiny rods,' she concludes. Kamperman looks for that something extra in a higher resolution in the material: even more tiny rods. Kamperman now tries to attain that higher resolution by, for example, making rods from so-called block copolymers. These are polymers which take on a certain shape through self-assembly. In this case, it is a helix. The result is a surface densely covered with countless spirals, like a cut-open mattress. Being flexible, the spirals can make firm contact and also let go easily again. Eat your heart out, gecko!

Explore further: Duct tape that never loses its stick

Related Stories

Duct tape that never loses its stick

January 7, 2005

Gecko feet hold key to development of self-cleaning adhesives Duct tape that never loses its stick. Bandages that come off without sticky residue or an "ouch." Gecko feet may hold the key to the development of synthetic ...

Secrets of the gecko foot help robot climb (w/ Video)

August 24, 2010

( -- The science behind gecko toes holds the answer to a dry adhesive that provides an ideal grip for robot feet. Stanford mechanical engineer Mark Cutkosky is using the new material, based on the structure of ...

Scientists trace gecko footprint, find clue to glue

August 25, 2011

Geckos' ability to scamper up walls with ease has long inspired scientists who study the fine keratin hairs on these creatures' footpads, believed responsible for the adhesion. Researchers at The University of Akron have ...

Humidity makes gecko feet stickier

October 15, 2010

Geckos have amazingly sticky feet. Their stickability comes from billions of dry microscopic hairs that coat the soles of their feet. However, when humidity increases, gecko feet stick even tighter to smooth surfaces, so ...

Copying geckos’ toes

September 5, 2011

Geckos are famous for their ability to walk up walls and scamper across ceilings. The dry-adhesive surface of geckos’ toes has inspired many attempts to copy this ability in an artificial material. Isabel Rodríguez ...

Recommended for you

Spore formation model could advance medicine

February 21, 2018

Michigan State University scientists have produced experimental and modeling results that shed light on how a particular type of enzyme functions during spore formation, potentially advancing human health and disease research.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.